Morphological Relationships between Wild and Cultivated Pears in Georgia

Abstract

214 individuals of 26 local, 9 introduced pear cultivars and 3 wild progenitor species of cultivated pear: Pyrus caucasica Fed.; P. balansae Decne. and P. pyraster (L.) Burgsd. have been evaluated by 27 morphological characters. 6 quantitative and 6 qualitative leaf and young shoot and 14 qualitative fruit descriptors have been used in multivariate statistical analysis. Leaf blade form have been analysed using Fourier's outline shape analysis method measuring 20 harmonics per leaf and 10 leaves per individual. 6 Principal Components have been used in Hierarchical Cluster Analysis and revealed close Euclidean similarity distances between 15 Georgian aboriginal pear cultivars and two wild species: P. caucasica (endemic of the Caucasus) and P. balansae (wild species native for Georgia). European wild pear - P. pyraster, was clustered with 9 introduced and 11 Georgian pear cultivars. The results of this study have shown that some local pear cultivars of Georgia are directly domesticated from the native wild pear species - P. caucasica and P. balansae. The other local cultivars might be obtained due to selective works by breeding of local landraces with introduced cultivars from different countries in historically different periods.